<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    .sliderbar {
        position: fixed;
        right: 0;
        bottom: 100px;
        width: 40px;
        height: 40px;
        text-align: center;
        line-height: 40px;
        cursor: pointer;
        color: #fff;
    }
    .con {
            position: absolute;
            left: 0px;
            top: 0px;
            width: 200px;
            height: 40px;
            background-color: purple;
            z-index: -1;
        }

    </style>
    <script src="./js/animate.js"></script>
</head>
<body>
    <div class="sliderbar">
        <span>←</span>
        <div class="con">问题反馈</div>
    </div>
    <script>
        var sliderbar = document.querySelector('.sliderbar');
        var con = document.querySelector('.con');
         // 当我们鼠标经过 sliderbar 就会让 con这个盒子滑动到左侧
        // 当我们鼠标离开 sliderbar 就会让 con这个盒子滑动到右侧
        sliderbar.addEventListener('mouseenter',function(){
            // animate(obj, target, callback);
            animate(con, -160, function(){
                // 当我们动画执行完毕，就把 ← 改为 →
                sliderbar.children[0].innerHTML = '→';
            })
        })
        sliderbar.addEventListener('mouseleave',function(){
            // animate(obj, target, callback);
            animate(con, 0, function() {
                sliderbar.children[0].innerHTML = '←';
            });
        })
    </script>
</body>
</html>